Hey! We (a group of 6 on gravel bikes) are going to be there on Friday of this week. The plan is to ride from the potash plant to the switchbacks on Shafer, and then turn around and go back. I hadn't quite realized how much elevation gain there is on the switchbacks up to the top - I was thinking that would be an option to extend up the switchbacks and ride to the Island in the Sky visitor center if we needed extra water, but it looks like that would be significant climbing.
I'm assuming that section from the end of the pavement on Potash Rd, to the bottom of the switchbacks, is fairly easy - it looks mostly like jeep road. How much sand is there?